Rehabilitating a Shoulder Impingement Injury

Ask any baseball or tennis player about the value of their powerful arm swing and they'll likely tell you they couldn't participate in their sport without it. That's why immediate treatment of pain in the shoulder is so critical to staying in the game.

The shoulder joint is formed by the bony connections of the upper arm, the collarbone and the shoulder blade, and is one of the body's most mobile joints. While functioning as a "ball and socket" joint, research shows that the arm can be placed in more than 16,000 different positions. For the shoulder joint to function properly and allow the greatest range of arm motion, 14 muscles and many small ligaments and tendons around the joint must work together, each contributing to the joint's overall function and health.

The shoulder's unique mobility belies its vulnerability. Poor blood supply, lack of bony stability and repetitive stresses associated with daily activities and overhead sports-related movements predispose the shoulder joint to injury. When the muscles and connective tissue become stressed and don't receive adequate blood to repair tissue and promote healing, shoulder injuries can occur.

Impingement Syndrome
A common shoulder injury is impingement syndrome, best described as a painful pinching or compression of muscle or connective tissue between the bones that comprise the shoulder. Categorized as an overuse injury, impingement syndrome occurs for many reasons. Muscles or connective tissue around the joint can become tired, weak or very loose, resulting in joint instability. The tissues no longer work together to keep the joint functioning properly, triggering a chain of events leading to injury. Tendons and ligaments may become irritated or swollen and in turn, impinge on other muscles or connective tissue.

There are two types of impingement conditions. Primary impingement is age-related and often seen in athletes over age 40, occurring when shoulder muscles weaken and tendons degenerate. Secondary impingement affects athletes of all ages and occurs when the front of the shoulder joint is unstable. Secondary impingement is associated with repetitive overhead or throwing motions that generate a lot of force, such as throwing a baseball or hitting a tennis ball with a racquet.

Shoulder impingement symptoms include pain, muscle weakness or fatigue, decreased range of motion and a reduced ability to control motion. Athletes such as baseball pitchers may experience a decline in their throwing speed or control, impacting performance. Most people will see a physician when the pain becomes too great or when they are unable to continue normal activities. On diagnosis, people with this condition often benefit from a referral to a physical therapist for rehabilitation.

Rehabilitation
Rehabilitation for a shoulder injury can take weeks or months. A clinical assessment of the shoulder joint will determine the type of impingement and possible causes of the condition. Following evaluation, physical therapists create an in-clinic and home rehabilitation program that helps to address the cause of the injury and reduce the likelihood of re-injury. Initial goals of rehabilitation include resting the muscles, decreasing pain and returning normal range of motion.

Muscle strengthening is key to rehabilitation. Many people with impingement syndrome have muscle imbalances: the muscles to the front of the shoulder joint are stronger than those to the back. Successful rehabilitation may consist of strengthening weaker shoulder muscles with light weights. Sometimes, muscles have stopped working altogether and therefore must be "re-trained" to work properly again. Strengthening can be specific to the rotator cuff, a term applied to a complex of four muscles responsible for joint control and shoulder rotation, a motion specific to throwing.

Once pain subsides and normal range of motion has returned, stretching, strengthening and gradual re-introduction to daily activities and sport follows. Athletes who participate in warm-weather sports such as baseball and softball may return to throwing slowly, progressing their training only when the shoulder has been allowed to acclimate to the overhead motion. Gradual acclimation helps to reduce injury risk.
Shoulder impingement syndrome is a painful experience and can prevent people from participating in sports or daily activities. Rehabilitation is important to helping to maintain normal shoulder function and to return people to the activities they enjoy.

For more information about shoulder impingement syndrome, call Minnesota Sports Medicine at 612-273-4800 or the Institute for Athletic Medicine's Throwing Injury Program at 612-672-7929.